(1) Field of the Invention
The present invention relates to a brace which provides encompassing pressure around the ankle to limit eversion and inversion of the ankle and the foot. In particular, the present invention relates to a custom fitted brace which extends over the ankle and provides encompassing pressure around the subtalar joint and the ankle joint to limit inversion and eversion of the ankle and the foot.
The subtalar joint consists of the articulation of the inferior surface of the talus and the superior surface of the calcaneus. The subtalar joint is a gliding joint permitting limited motion in all directions. The basic motions are inversion and eversion. Inversion is turning of the foot such that the medial side (inside) of the foot is upward. Eversion is turning of the foot such that the lateral side (outside) of the foot is upward. Inversion and eversion is shown in FIG. 5 of The Foot: Examination and Diagnosis, Dr. Ian J. Alexander, Page 9. The ankle joint is formed by the inferior ends of the tibia and the fibula and the superior surface of the talus. The ankle joint is a hinged joint allowing dorsiflexion and plantar flexion. Dorsiflexion is bending the foot backward or upward. Plantar flexion is bending the foot downward. Dorsiflexion and plantar flexion is shown in FIG. 4 of The Foot: Examination and Diagnosis, Dr. Ian J. Alexander, Page 8. To limit inversion and eversion of the ankle and the foot, movement of the subtalar must be limited. However, to allow the patient to be ambulatory, dorsiflexion and plantar flexion of the foot must not be substantially affected.
(2) Prior Art
Definitions for all the relevant medical terms can be found in Dorland's Medical Dictionary Shorter Edition, (Saunders Company, 1980). In addition, specific information relating to the ankle and the foot can be found in The Foot: Examination and Diagnosis, Ian J. Alexander, (Churchill Livingstone Inc., 1990).
The prior art has described various types of ankle braces and supports. Illustrative are U.S. Pat. Nos. 101,743 to King; 143,537 to Silberschmidt; 1,397,095 to Hamilton; 4,409,976 to Pence; 4,433,682 to Badra; 4,844,094 to Grim; 5,135,473 to Epler et al; and 5,185,000 to Brandt et al.
In particular, U.S. Pat. No. 4,926,846 to Nassar describes an ankle wrap for limiting the intermalleolar expansion in the ankle during physical activity. The wrap consists of two separate straps which are wrapped around the ankle to provide compressive pressure to the mortise. The straps are wrapped completely around the ankle and are secured end to start by a hook and loop closure.
None of the prior art patents show an ankle brace which is easily and quickly applied to the ankle and which provides the necessary pressure to limit the inversion and eversion of the ankle and foot and which also supports the ankle without being bulky or uncomfortable to wear. Thus, there remains a need for an ankle brace which is custom fitted to the user to provide encompassing pressure around the ankle to limit inversion and eversion of the ankle and the foot while allowing dorsiflexion and plantar flexion of the ankle and the foot to allow the user to remain ambulatory.